Thomas,

Click on this link.
Fill in the blanks and click submit.
Click on the unit name.
Now, click on search for a solder and fill in only the last name, or go to the list of all soldiers and go down the list until you find your man. Do not forget he may be there but his name may not be spelled right.

http://www.itd.nps.gov/cwss/regiments.htm

Good hunting!
Gary D.Bray